X0306 4 2021-10-06 0 0001828522 eFFECTOR Therapeutics, Inc. EFTR 0001709976 Gallagher Brian M. Jr. C/O EFFECTOR THERAPEUTICS, INC. 11120 ROSELLE ST SUITE A SAN DIEGO CA 92121 1 0 1 0 Stock Option (Right to Buy) 11.36 2021-10-06 4 A 0 40000 0.00 A 2031-10-05 Common Stock 40000 40000 D The shares subject to the option will vest in substantially equal monthly installments over three years, commencing on August 25, 2021, subject to the Reporting Person's continued service with the Issuer through each vesting date. /s/ Michael Byrnes, Attorney-in-Fact for Brian M. Gallagher, Jr. 2021-10-08